import { relayServerFailure } from '../../../../../utils/fetchFailureMessage';
import { asDenial } from '../../../../../utils/booking/appointmentGuardOutcome';
import { BookingStorageUnavailableError } from '../../../../../utils/booking/bookingOperation';

const FALLBACK = "We couldn't book this appointment. Please try again.";

// What a patient reads when a booking failed for a reason the form did not expect. Only an answer from
// the server can carry a sentence written for people; anything else says the booking did not go through.
export const bookingFailure = (error: unknown): string => {
    // Nothing was sent: the device could not keep the booking, and the sentence says what to change.
    if (error instanceof BookingStorageUnavailableError) return error.message;
    const answered = typeof (error as { status?: unknown } | null)?.status === 'number';
    return answered ? relayServerFailure(error, FALLBACK) : FALLBACK;
};

// A 403 is the practice refusing what was chosen, not a failure to retry: the server's own sentence,
// as a denial, for the patient to read where they choose again. Undefined for anything else.
export const bookingRefusal = (error: unknown): string | undefined => {
    if ((error as { status?: unknown } | null)?.status !== 403) return undefined;
    return asDenial(relayServerFailure(error, FALLBACK));
};